I have plenty of bandwidth here & I’ve checked that the TV doesn’t have any ugly motion smoothing filters on. It appears similar on my laptop too.
I mean, I can see how the BBC has to compress its stream to send them out, but if that’s leading to this nasty smoothing & smudged look, they should think again.
Or perhaps it’s the way they scanned the film? Or maybe the film is horrible in the original – much of the lighting is very poor, IMHO.